The present invention relates to a chair convertible into a chaise-lounge. A chaise-lounge is traditionally made up of three portions with different inclinations: a backrest portion, a seat portion and a foot-rest portion. The seat portion and the foot-rest portion usually have inclinations opposite to one another with respect to a horizontal plane so that, when the user is sitting on a chaise-lounge, his knees are usually at a greater height than his pelvis and feet.